Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings C h a p t e r 13 The Spinal Cord, Spinal Nerves, and Spinal Reflexes PowerPoint® Lecture Slides prepared by Jason LaPres Lone Star College - North Harris Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Spinal Cord  The Spinal Nerve  Each side of spine  Dorsal and ventral roots join  To form a spinal nerve  Mixed Nerves  Carry both afferent (sensory) and efferent (motor) fibers

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Spinal Nerves and Plexuses  Three Connective Tissue Layers of Spinal Nerves  Epineurium  Outer layer  Dense network of collagen fibers  Perineurium  Middle layer  Divides nerve into fascicles (axon bundles)  Endoneurium  Inner layer  Surrounds individual axons

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Spinal Nerves and Plexuses  Peripheral Nerves  Interconnecting branches of spinal nerves  Surrounded by connective tissue sheaths